Timepiece dial

ABSTRACT

A TIMEPIECE DIAL OF TRANSLUCENT MATERIAL HAS A LIGHT SOURCE SUCH AS AN INCANDESCENT ELECTRIC LIGHT IN THE MATERIAL OF THE DIAL WHICH ILLUMINATED TO SHOW THE HOUR MARKERS IN RELIEF. THE DIAL PREFERABLY HAS INTERNAL RE-   FRACTING SURFACES TO REFRACT LIGHT THROUGH THE PART BEARING THE HOUR MARKERS.

United States Patent Ofiice 3,609,960 Patented Oct. 5, 1971 U.S. Cl.58-50 Claims ABSTRACT OF THE DISCLOSURE A timepece dial of translucentmaterial has a light source such as an incandescent electric light inthe material of the dia-1 which is illuminated to show the hour markersin relief. The dial preferably has internal refractng surfaces torcfract light through the part bearing the hour markers.

The present invention relates to timepece dials Com posed of translucentmaterial.

It has already been proposed to make a dial in a translucent material,for example certain types of glass, under which a source of lightdirectly or indirectly lights up the dial, ditfusing the light so thatthe hour markers and the hands are opaque against a luminous ground.

It is also known -to use an elect'ic bulb in an optical conductorsurrounding the dial, lighting of the lamp being achieved by an outsidepush-piece.

However, the fitting of an electric lamp or an optical conductor underor around a wrist-watch dial is virtually impossible without increasingthe size.

The present invention has for its precise object a timepiece dial in atranslucent material which obviates these drawbacks, characterized bythe fact that it comprises a light source inserted in the dial material.

The accompanyng drawings show, by way of example, an embodinent of theinvention.

The single figure shows a cross-section of the invention.

The single figure shows a dial body member 1 of translucent glassprovided with blind bores or holes 7 made in the dial and designed torefract and direct difiused light from a light source towards the faceof the dial. These holes locally ditluse the incident light lluxparticularly in the direction from which the dial is visible.

A cavity is provided in the dial and illuminating means in the form oflamp 20, which comprises a filament 3, is dsposed within the cavity.Electrical conductors 4, 5 are connected to the filament 3 and extendexteriorly of the dial body member and are connected to a battery (notshown) through a switch (not shown) which is positioned on the timepiece casing.

The contrast efiect allows the viewer to clearly distinguish the hourmarkers 6 as luminous points of the surface of a darker dial and enablesuse of a weaker light source and, therefore, lower power Consumption,than would otherwise be required. The hour market-s 6 are optional andare preferably placed above holes 7, as shown.

Hour markers or timing indicia 6 can be either made in opaque materialappearing dark against a lighted ground, or be made by providing anopaque coating on the dial 'and tracing the hour markers so that thelight shines through and they are illuminated against a dark ground. Inother words, the timing indicia are composed of a material having adillerent light absorption property than the dial surface.

Lamp 20 can either be made independent of the dial, or in one piece withthe dial as described in the previous example. i

It is possible to provide two or more light sources in a dial to provideuniform illumination thereof.

Instead of an incandescent light it is also possible to provide afluorescent light.

What is claimed is:

1. In a timepece dial composed of translucent material having opposedsurfaces and having means therein defining a cavity, a light sourcepositioned in said cavity, and timing marks arranged on one of saidsurfaces of 'the dial, the improvement comprising means defining blindbores in said dial in the other o' said surfaces for reflecting lightron the light source towards said one surface of the 2. A dial accordingto claim 1, wherein said blind bores are arranged in alignment with saidtiming marks.

3. A timepece dial comprising: a body member composed of translucentmaterial having opposed major surfaces and having therein between saidopposed major surfaces means defining a cavity; timing indiciapositioned on one of said major surfaces, said timing indicia having adifferent light absorption property than said one major surface;illuminating means dsposed within said cavity for illuminating said bodymember with light; and means defining a plurality of blind bores in saidbody member opening at the other of said major surfaces and positionedin superposed relationship relative to respective ones of said timingindicia for directing said light towards said one major surface; wherebysaid timing indicia are highlighted with respect to the remainder ofsaid one major surface.

4. A timepece dial according to claim 3, wherein said timing indicia arecomposed of a material which is more' light absorptive than said onemajor surface.

5. A timepece dial according to claim 3; wherein said one major surfaceexclusive of those areas on which said timing indicia are positioned iscomposed of a material which is more light absorptive than said timingindicia.

References Cited UNITED STATES PATENTS l,8'88,366 11/1932 Willens 240--12,680,8l3 6/1954 Doyle 5^8-50 X 2, 745 ,946 5/ 1956 Protzmann 2.40-2.12,9'l6,*871 12/1959 Wegner 58-50 3,043,038 7/l962 Marble 58-50' X3,2l4,577 10/1965 Protzmann 240-1 X 3,278,740 10/ 1966 Madansky 240--2.13,32'8,570 6/ 1967 Balchunas `%lo-2.1 3,349,235 10/ 1967 Kolodziej et al240-2.1

F OREIGN PATENTS 1,003,314 11/1951 France 58-50 RICHARD B. WILKINSON,Primary Examiner S. A. WAL, Assistant Examiner U.S. Cl. X.R. 58- l27;240-1

